• Clean wooden parts of exterior doors and windows with mild detergents or soapy water only; under no circumstances use acid-, alcohol- or ammonia-based cleaners.
• You can clean glass with normal commercially available cleaners, but be careful not to get them on the silicone or varnish; never use abrasive products (wire scouring pads and the like).
• Lubrication results in less hardware friction and reduces oxidation on all moving parts (hinges, locks, fittings, etc.), which need lubricating a couple of times a year with mineral oil.

What this elasticity also does is make the water-based varnish slightly thermoplastic, which means it softens when exposed to heat. The action of rubbing generates heat on the surface, causing the varnish to soften and thus making the pigments easy to remove from the frame coating since they’re found on the surface of the film and not just inside the varnish. As the layer of removed varnish is infinitesimally small, you won’t see any reduction in the protection from weathering provided by the varnish. You’ll find that less and less colour comes off once you’ve cleaned the frames a few times.Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.

• the level of exposure to sunlight
• the type of wood
• the colour of the preservative

Exposure to sunlight: window and door frames fitted flush with the outside wall or without any external shelter (e.g. porch, etc.) or facing south-west (in the case of the northern hemisphere) or installed in hot countries (e.g. Greece, Middle East, Spain, Portugal, etc.) will experience more noticeable changes in colour due to their greater exposure to solar radiation. Type of wood: wood can be split into two categories:

• Non-tannic wood (e.g. Meranti): wood exposed to sunlight tends to go yellow or darken due to the products that form as a result of the lignin in the wood cells being broken down.
• Tannic wood (e.g. Oak, Teak): wood exposed to sunlight tends to discolour as the compounds contained in the wood cell – which are what give the species its colour – begin to break down. This colour change is more noticeable where the wood features a deeper coloured grain (e.g. Teak) since the grain’s natural substances are more prone to being broken down by sunlight.

Colour of the preservative: in the case of colourless preservatives, the change in the colour of the wood is considerable and can be seen after just a few months of exposure. This change will be far less noticeable when using darker tinted preservatives. This is because the clear iron oxides used to tint the preservative have a special property that allows them to absorb the UV component of solar radiation. Moreover, since iron oxides offer excellent heat resistance and are exceptionally UV stable, they provide the wood with better long-term protection.

Solution:

If your windows and doors have a clear finish and are highly exposed and/or installed in a hot country, at least once every six months you can use a rag to apply the mild water-based detergent T.CLEAN RIO VERDE RR1050 followed by the water-based wood reviver T.TOP+ RIO VERDE RR1250

The binder component of water-based varnishes consists of acrylic resin particles dispersed in an aqueous emulsion, which is produced using surfactants or emulsifiers. The latter chemical substances are made up of a hydrophobic part (which bonds with the acrylic resin given that it is not water soluble) and a hydrophilic part (which bonds with the water). Even when the film of varnish has dried, the surfactants stay inside the film until they have been washed away completely by rainwater. When surfactants locked inside the film of varnish come into contact with rainwater and/or moisture condensing at night, they generate clear whitish patches that disappear as soon as they are no longer affected by water (once it has evaporated). These patches can be attributed to the solubility of the surfactant inside the film. If the film comes into contact with water on subsequent occasions, each episode will be less pronounced than the last, to the point where it disappears altogether once all the surfactant has been washed away.

Solution:

Do nothing, just leave the frames to dry naturally. It’s very important you don’t scratch at the whitish patch since the film has not hardened fully at this stage and could be damaged irreparably in this partly softened state. You can wipe off water with a soft cloth without damaging the varnish. This phenomenon will become less noticeable as time goes by and, in time, will simply cease to occur. Consequently, you don’t have to take any kind of action. However, if you want to do something to remedy the situation anyway, you can always proceed as follows once the whitish patches have disappeared and the frame is completely dry:

• If dealing with fairly significant whitish patches: use a rag to apply the water-based wood reviver T.TOP+ RIO VERDE RR1250, regardless of the tint or colour of the frame.

Solution:

As soon as atmospheric humidity has returned to normal – provided the high levels have not lasted for too long (more than 7 days) – shutters will return to more or less their original size. So do not shave down the shutter with a plane. After the first two or three swelling episodes caused by atmospheric humidity, the wood stabilizes, meaning it becomes much less of a problem. If atmospheric humidity levels remain high for an extended period of time (longer than 15 days), the swelling, beyond a certain limit, will not go away altogether. In this case, the first thing to do is adjust the hardware and then, if this is not enough, the sides will need shaving down. The wood exposed as a result will need re varnishing.